1. Field of the Invention:
This invention relates to a limited slip differential and, more particularly, to a device for limiting the differential motion by utilizing frictional force generated through the contact of a plurality of frictional materials by the external operation.
2. Description of the Prior Art:
There have been proposed some types of devices which limit the differential motion by utilizing the frictional force generated through the contact of a plurality of frictional materails by the external operation.
The first type of the device has been disclosed in the Japanese Utility Model Public Disclosure (KOKAI) No. 68846/84, which comprises a hydraulic cylinder disposed at the outside of a differential carrier (hereinafter referred to as carrier), a lever operated by the hydraulic cylinder and engaging a hub in the carrier to shift a side gear in a differential gear through the hub and a plurality of frictional materials disposed between the side gear and a differential case (hereinafter referred to as case).
The second type of the device has been disclosed in the Japanese Utility Model Public Disclosure (KOKAI) No. 70952/84 and the Specification of U.S. Pat. No. 3,894,446, which has a pump provided at the outside of a carrier. The pressure generated by the pump is directed once to a shaft supported rotatably in the carrier and further directed from the shaft to an operational chamber provided in a member supported rotatably relative to the shaft, thereby permitting to contact frictional materials with each other due to this pressure.
The third type of the device has been disclosed in the Japanese Utility Model Public Disclosure (KOKAI) No. 73430/86, which comprises a first piston shiftably disposed in a carrier to be hydraulically operated, a second piston shiftably disposed in a case and engaging frictional materials and a thrust bearing interposed between both pistons.